On-line Fault Diagnosis of Launch Vehicle Thrust Loss Based on Parameter Estimation Method

The online diagnosis of a single thrust drop fault of the launch vehicle’s four engines is studied. Based on the simplified space motion equation of the launch vehicle, the relationship between thrust and overload acceleration information is established. Then the engine thrust is identified by the least squares method of forgetting factor, and the relationship between the identified thrust and the true thrust is linearly fitted to realizes the online diagnosis of thrust drop faults. Combined with overload location strategy, the fault location of four engines was realized. The digital simulation results show that the proposed method can diagnose the engine thrust loss fault accurately and quickly, and verify the effectiveness under the wind disturbance.